Former Nigerian first lady Patience Jonathan is claiming ownership of bank accounts allegedly worth $31.5 million that have been frozen in a corruption investigation, prompting anti-corruption groups to demand her prosecution.

The wife of former President Goodluck Jonathan filed suit asking the Federal High Court in Lagos to unfreeze five U.S. dollar accounts at Nigeria's Skye Bank. They were frozen by the Economic and Financial Crimes Commission in July.

Separately, her lawyer sent a letter to the commission saying $15 million of the money was a government payment for medical bills she incurred in London in 2013.

Nigerians have taken to social media to deride that claim, asking if she planned to heal the entire world or was buying eternal life. But some accused the anti-graft commission of subjecting her and others to “trial by media.”

The commission has detained hundreds of people in a yearlong investigation of tens of billions of dollars missing from the state treasury that has not produced any successful prosecutions.

The commission did not immediately respond to requests for comment on the lawsuit and letter, which were dated last week and obtained by The Associated Press.

President Goodluck Jonathan left office in May 2015 after being voted out.

Nigeria's Socio-Economic Rights and Accountability Project, a civil society group, demanded that the attorney general immediately undertake criminal proceedings against the former first lady.

Nigerian media quoted unidentified anti-corruption commission officers as saying all but one of the frozen accounts were set up in the names of domestic workers, though the former first lady was the sole signatory.

A former senior presidential aide, a lawyer and a bank official are among people named in the corruption case that alleges graft and money laundering.